gjgm
Well-Known Member
I thought that was the question ?
Fire! - dehumidifier O/B catches alight.........Help!
- Thread starter mjf
- Start date
I thought that was the question ?
benjenbav
Well-Known Member
Glad to hear the fire was sorted out without anyone getting hurt and the damage repaired.
It made me think that, over the course of many years, I have happily left boats with electric dehumidifiers running on timers for weeks at a time. I won't be doing that again in a hurry.
Also, thanks sarabande. I was so impressed by that clip of water mist extinguishers in action that I have already placed an order. I hadn't been aware of them before at all and the idea of just having to use one extinguisher for almost any type of domestic fire rather than trying to remember which is the right one to use at a time when my decision-making capacity might not be at its peak is quite reassuring.
It made me think that, over the course of many years, I have happily left boats with electric dehumidifiers running on timers for weeks at a time. I won't be doing that again in a hurry.
Also, thanks sarabande. I was so impressed by that clip of water mist extinguishers in action that I have already placed an order. I hadn't been aware of them before at all and the idea of just having to use one extinguisher for almost any type of domestic fire rather than trying to remember which is the right one to use at a time when my decision-making capacity might not be at its peak is quite reassuring.
Hurricane
Well-Known Member
Thanks for posting
Gives us all a "wake up call"
My insurance stipulates a fire blanket in the galley.
But a smoke detector sounds a very sensible idea.
Gives us all a "wake up call"
My insurance stipulates a fire blanket in the galley.
But a smoke detector sounds a very sensible idea.
rafiki_
Well-Known Member
Mike, many thanks for sharing this with us. And fantastic that you had a result with your insurer, and no long term harm done.
Regarding dehumidifier traps, we used to use these on our sports cruiser to great effect. With our Azi, the interior volume seems to be too great for these to be effective, so we use a Meaco dessicant dehumidifier, and leave this on when we a not on board over the winter. It is very effective. I do worry about the fire risk though.
Regarding dehumidifier traps, we used to use these on our sports cruiser to great effect. With our Azi, the interior volume seems to be too great for these to be effective, so we use a Meaco dessicant dehumidifier, and leave this on when we a not on board over the winter. It is very effective. I do worry about the fire risk though.
jfm
Well-Known Member
Wow, thanks for that write up M. I know you mentioned it over a glass of wine at LIBS but to read the full story above does indeed bring it home.
I'll look into water mist - thanks.
Your quick action saved the day, and at sea quick action must be critical. For that reason it's worth mentioning the seafire zoned alarm system. I know this is horse bolted/smug sounding territory, but if you were underway on the flybridge and had a fire in a cabin it could be too late by the time you saw the flames. So it is surely worth spending £2k on a system that tells you WHERE the fire is. you can have a seafire smoke sensor in every cabin wired back to the computer, heat detectors in engine room and galley, and also sensors in other risk areas which in my case I decided was behind the laundry equipment and in the airco chamber. Banshee hooters in a couple of places alert the whole boat and the Seafire panel tells you WHERE the fire is. It's worthwhile considering installing these and the SeaFire agents in Southampton area seemed very good when I bought from them and prepared a customised wiring diagram for free with the hardware purchase
I'll look into water mist - thanks.
Your quick action saved the day, and at sea quick action must be critical. For that reason it's worth mentioning the seafire zoned alarm system. I know this is horse bolted/smug sounding territory, but if you were underway on the flybridge and had a fire in a cabin it could be too late by the time you saw the flames. So it is surely worth spending £2k on a system that tells you WHERE the fire is. you can have a seafire smoke sensor in every cabin wired back to the computer, heat detectors in engine room and galley, and also sensors in other risk areas which in my case I decided was behind the laundry equipment and in the airco chamber. Banshee hooters in a couple of places alert the whole boat and the Seafire panel tells you WHERE the fire is. It's worthwhile considering installing these and the SeaFire agents in Southampton area seemed very good when I bought from them and prepared a customised wiring diagram for free with the hardware purchase
l'escargot
Well-Known Member
The question I answered was: "..I'm wondering, do carbon monoxide detectors double up as smoke detectors? (I have two of those on board)...". So the answer is no if they are just CO detectors, as inferred, and not combined CO/smoke detectors as per your link.
I was just qualifying it as it would be dangerous for someone to get the impression that all CO detectors also detect smoke - they don't.
superheat6k
Well-Known Member
A very salutary tale.
Seemingly the issue here is with compressor driven refrigerant de-humidifiers, yet I expect everyone one of us has a compressor driven fridge in our kitchen, and also in our galleys.
Most of these electrical appliance fires are caused by the thermostatic switches arcing when the load is switched off, and induction motors do pack a punch when the power is switched off. If the arcing contacts become excessively dirty the inductive discharge becomes concentrated in a smaller area of the contacts, increasing the temperature of the arc, and this can then ignite the plastic material in which it is housed. The result is the whole thing catching fire.
I wonder is a simple capacitor, AKA the ubiquitous Condenser on older car ignition systems, could be simply added to these thermostats to suppress the arc and at least reduce the risk of arc caused fire.
Nice to see your insurance firm were so positive with the claim situation. I think all of us rely on the spin of an insurance firm, not so often the support is really seen to back up what we pay for.
Seemingly the issue here is with compressor driven refrigerant de-humidifiers, yet I expect everyone one of us has a compressor driven fridge in our kitchen, and also in our galleys.
Most of these electrical appliance fires are caused by the thermostatic switches arcing when the load is switched off, and induction motors do pack a punch when the power is switched off. If the arcing contacts become excessively dirty the inductive discharge becomes concentrated in a smaller area of the contacts, increasing the temperature of the arc, and this can then ignite the plastic material in which it is housed. The result is the whole thing catching fire.
I wonder is a simple capacitor, AKA the ubiquitous Condenser on older car ignition systems, could be simply added to these thermostats to suppress the arc and at least reduce the risk of arc caused fire.
Nice to see your insurance firm were so positive with the claim situation. I think all of us rely on the spin of an insurance firm, not so often the support is really seen to back up what we pay for.
mjf
Well-Known Member
Yep - I have a Meaco now too and I am astonished that it needs to be emptied daily when I am O/B and its run in the same spot as the compressor type that caught fire. The Meaco also throws out a bit of warm air too and has a de-ion function too that helps clean the air.
mjf
Well-Known Member
I recon that not running a compressor is safer as less load than a fan that dries the soaked dessicant in the replacement, there is still a risk. leaving a battery charger on is a risk too but where do you stop.?
mjf
Well-Known Member
Got to agree jfm, a panel is the way to go.
Seeing this caused me to rethink the whole fire issue O/B - the boat of course is completely different to a shore building where elect items are in the main plugged in to sockets etc.
I understood this more when I saw how complicated the panels where and what they hid during the relining process.
In a shore home you don't have transformers for nav gear under the saloon sofa, nor galley extractor fans behind built in sideboards for example. As I mentioned most of us on here have built in fire fighting systems in E/R and Laz etc but no detection panel for accommodation sensors which seems to me an oversight now I have had a fire.
As you point out speed is the issue here, I was surprised in the short time between my two attempts how the fire seat had grown. What amazed me afterwards was the small amount of actual fire damage there was compared with the smoke/powder mix that went everywhere despite being used in confined space and re-closed door after 20/30 sec.
Seeing this caused me to rethink the whole fire issue O/B - the boat of course is completely different to a shore building where elect items are in the main plugged in to sockets etc.
I understood this more when I saw how complicated the panels where and what they hid during the relining process.
In a shore home you don't have transformers for nav gear under the saloon sofa, nor galley extractor fans behind built in sideboards for example. As I mentioned most of us on here have built in fire fighting systems in E/R and Laz etc but no detection panel for accommodation sensors which seems to me an oversight now I have had a fire.
As you point out speed is the issue here, I was surprised in the short time between my two attempts how the fire seat had grown. What amazed me afterwards was the small amount of actual fire damage there was compared with the smoke/powder mix that went everywhere despite being used in confined space and re-closed door after 20/30 sec.
KevB
Well-Known Member
+1 for the meaco, much more efficient than our old compressor type and much quieter. I've just ordered a fire alarm for the boat thanks to your recent experience.
Piers
Well-Known Member
What a salutory story. What was the make and model of the dehudim machine?
rafiki_
Well-Known Member
When off the boat, we just pipe the water into the galley sink which then goes overboard. No idea how much this extracts, as have never used the reservoir. The added heat can be a Brucie bonus when on board in the winter. Throws out a bit of heat before th Eber gets going.
mjf
Well-Known Member
Good point as cant recall exactly but have a feeling it was a Wickes own brand - oddly it had the water catchment at the top so very easy to empty when not on free flow. The fire heat melted the clear plastic catchment container which was over 1/2 full and dumped the water onto the compressor below without extinguishing the fire!
Falcoron
Well-Known Member
Are these safe to keep running over winter when not on the boat? i would love to put one in my old ocean 30, but need to be sure these would be safe to do so.
Any toughts on how to run these safely when the boat is empty? Also how do you attach a drain hose to these to avaoid a resovior overflowing?
Thanks
rafiki_
Well-Known Member
The Maeco DL8 (I think) Junior is a desiccant drier not Peltier. The culprit in Mike's boat was a Peltier type. The Maeco comes with a hose that I pipe into the galley sink, so any water drains away. I have not heard of any issues with the Maeco dehumidifier. Mine is 3 years old, and I set it to activate for a couple of hours a day, using a timer.
NoviceRod
Well-Known Member
If the timer switches off power to the whole unit, this can create situations where the drum may overheat and be a fire risk. As you may have noticed, when you switch off the Meaco without switching off the mains supply, it continues to run for a few minutes to cool the drum. Desiccant driers can be a fire risk if used with a time switch that controls the mains supply. I leave mine running continuously, and it starts/stops as required to manage the humidity. I use the 'two thumbs' setting.
Andrew M
Well-Known Member
I run 2 of the Eco Air dessicant type, draining into heads sinks in both cases and in winter left on full time. One of my original ones seemed to cut out and not come back on so it went back to Eco Air through their very helpful Customer Services Dept for repair, hasn't missed a beat since. In all communication with them they have been keen to impress on me the importance of regularly cleaning the air filter. I have looked for any implication of Eco Air ones having overheat or fire problems and haven't found anything yet so am comfortable with them running full time. They do put out a little bit of warmth with the exhausted air which I am fine with, thinking it might just raise the local air temp a tiny bit and appears to me a welcome by-product or their dehumidifying process. They def drag moisture out as the drain pipe can be seen with droplets running through it.
A worrying start to this thread from MJF but glad it ended up being contained and controlled, well done with quick thinking. Another aspect from reading this is that I'll be looking into those water mist extinguishers.
Andy
A worrying start to this thread from MJF but glad it ended up being contained and controlled, well done with quick thinking. Another aspect from reading this is that I'll be looking into those water mist extinguishers.
Andy
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Piers
Well-Known Member
Hi All, I 've searched this thread but can't find how I determine whether a de-humidifier is dessicant or whatever. Have i missed something?
mjf
Well-Known Member
Piers, as said above the fire was caused by a compressor driven unit, the replacement is desiccant and considered safer.
I use mine draining into the galley sink on low setting and it's very cheap to run and maintains 50/55% RH
I think using timer a risk as others have said the fan continues if you switch it off when it's running and it's the fan that cools the hot chemical so needs power for it to cool and recharge the system. In winter you get the small heat advantage over the compressor type which works poorly in cool temperatures anyway.. So blows a warm air upwards whilst the galley sole has a greenhouse heater.
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